Delivery systems for prosthetic heart valve

ABSTRACT

A delivery apparatus for a prosthetic heart valve includes a shaft, an inner balloon, and an outer balloon. The shaft has a lumen extending from a proximal end portion to a distal end portion and a plurality of openings formed in the distal end portion. The shaft is configured such that a fluid can flow through the lumen and the openings. The inner balloon has end portions and a center portion disposed between the end portions. The inner balloon is mounted on the distal end portion of the shaft and is in fluid communication with the openings of the shaft. When the inner balloon is inflated with the fluid, the end portions expand farther radially outwardly than the center portion. The outer balloon is mounted to the shaft and disposed over the inner balloon. The outer balloon is configured to fully expand after the inner balloon at least partially expands.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/136,735, filed on Apr. 22, 2016, issuing as U.S. Pat. No. 9,795,477,which is a continuation of U.S. patent application Ser. No. 13/559,284,filed Jul. 26, 2012, issued as U.S. Pat. No. 9,339,384, which claims thebenefit of U.S. Provisional Application No. 61/512,328, filed Jul. 27,2011. Each of these applications is incorporated herein by reference.

FIELD

The present disclosure concerns embodiments of delivery systems forimplanting prosthetic heart valves.

BACKGROUND

Prosthetic cardiac valves have been used for many years to treat cardiacvalvular disorders. The native heart valves (such as the aortic,pulmonary and mitral valves) serve critical functions in assuring theforward flow of an adequate supply of blood through the cardiovascularsystem. These heart valves can be rendered less effective by congenital,inflammatory or infectious conditions. Such damage to the valves canresult in serious cardiovascular compromise or death. For many years thedefinitive treatment for such disorders was the surgical repair orreplacement of the valve during open heart surgery, but such surgeriesare prone to many complications. More recently a transvascular techniquehas been developed for introducing and implanting a prosthetic heartvalve using a flexible catheter in a manner that is less invasive thanopen heart surgery.

In this technique, a prosthetic valve is mounted in a crimped state onthe end portion of a flexible catheter and advanced through a bloodvessel of the patient until the prosthetic valve reaches theimplantation site. The prosthetic valve at the catheter tip is thenexpanded to its functional size at the site of the defective nativevalve such as by inflating a balloon on which the prosthetic valve ismounted. Alternatively, the prosthetic valve can have a resilient,self-expanding stent or frame that expands the prosthetic valve to itsfunctional size when it is advanced from a delivery sheath at the distalend of the catheter.

A prosthetic valve that has a relatively large profile or diameter inthe compressed state can inhibit the physician's ability to advance theprosthetic valve through the femoral artery or vein. More particularly,a smaller profile allows for treatment of a wider population ofpatients, with enhanced safety. Thus, a need exists for delivery devicesthat can minimize the overall crimp profile of the prosthetic valve forthe delivery of the prosthetic valve through the patient's vasculature.

Relatively long delivery devices, such as used for transfemoral deliveryof a prosthetic valve, can inhibit the physician's ability to positionthe prosthetic valve precisely at the desired implantation site becausethe forces applied to the handle at one end of the delivery device cancause unwanted movement of the prosthetic valve at the opposite end ofthe delivery device. Thus, a need exists for delivery devices that allowa physician to accurately control the positioning of the prostheticvalve at the desired implantation location.

When introducing a delivery device into the body, an introducer sheathtypically is inserted first and then the delivery device is insertedthrough the introducer sheath and into the body. If the prosthetic valveis mounted on a balloon catheter, the prosthetic valve can contact theinner surface of the introducer sheath and may become dislodged from itspreferred location on the balloon catheter, depending on the size of thecrimped valve. Thus, a need exists for delivery devices that can betterretain the crimped valve at its desired location on the balloon catheteras it is advanced through an introducer sheath.

SUMMARY

Described herein are systems and methods for delivering prostheticdevices, such as prosthetic heart valves, through the body and into theheart for implantation therein. The prosthetic devices delivered withthe delivery systems disclosed herein are, for example, radiallyexpandable from a radially compressed state mounted on the deliverysystem to a radially expanded state for implantation using an inflatableballoon (or equivalent expansion device) of the delivery system.Exemplary delivery routes through the body and into the heart includetransfemoral routes, transapical routes, and transaortic routes, amongothers. Although the devices and methods disclosed herein are particularsuited for implanting prosthetic heart valves (e.g., a prosthetic aorticvalve or prosthetic mitral valve), the disclosed devices and methods canbe adapted for implanting other types of prosthetic valves within thebody (e.g., prosthetic venous valves) or other types of expandableprosthetic devices adapted to be implanted in various body lumens.

In some embodiments, a delivery apparatus for implanting a prosthetic,transcatheter heart valve via a patient's vasculature includes anadjustment device for adjusting the position of a balloon relative to acrimped prosthetic valve (and/or vice versa). A balloon catheter canextend coaxially with a guide (or flex) catheter, and a balloon memberat the distal end of the balloon catheter can be positioned proximal ordistal to a crimped prosthetic valve. The balloon member and the crimpedprosthetic valve can enter the vasculature of a patient through anintroducer sheath and, once the balloon member and the crimpedprosthetic valve reach a suitable location in the body, the relativeposition of the prosthetic valve and balloon member can be adjusted sothat the balloon member is positioned within the frame of the prostheticvalve so that the prosthetic valve eventually can be expanded at thetreatment site. Once the crimped prosthetic valve is positioned on theballoon, the prosthetic valve is advanced to the vicinity of thedeployment location (i.e., the native aortic valve) and the adjustmentdevice can further be used to accurately adjust or “fine tune” theposition of the prosthetic valve relative to the desired deploymentlocation.

An exemplary method of implanting a radially compressible and expandableprosthetic device (e.g., a prosthetic heart valve) in the heartcomprises: (a) introducing a delivery device into the body of a patient,the delivery device comprising a handle portion, an elongated shaftextending from the handle portion, the shaft having a distal end portionmounting an inflatable balloon and a prosthetic heart valve in aradially compressed state; (b) advancing the distal end portion of thedelivery device toward the native heart valve until the prosthetic valveis within or adjacent the annulus of the native heart valve; (c)positioning the prosthetic heart valve at a desired implantationposition within the annulus of the native by rotating an adjustmentdevice coupled to the handle portion and the shaft to cause the shaftand the prosthetic valve to move distally and/or proximally relative tothe handle portion until the prosthetic heart valve is at the desiredimplantation position; and (d) after the prosthetic heart valve has beenmoved to the desired implantation position, inflating the balloon tocause the prosthetic heart valve to radially expand and engage theannulus of the native heart valve.

An exemplary delivery apparatus for implantation of a prosthetic device(e.g., a prosthetic heart valve) in the heart comprises an elongatedshaft comprising a proximal end portion and a distal end portion, aninflatable balloon, and a valve mounting member. The balloon is mountedon the distal end portion of the shaft. The valve mounting member isdisposed on the distal end portion of the shaft within the balloon andis configured to facilitate frictional engagement between the prostheticheart valve and the balloon when the prosthetic heart valve is mountedin a radially compressed state on the balloon and surrounding themounting member. The mounting member comprises at least onelongitudinally extending fluid passageway through which an inflationfluid in the balloon can flow.

In some embodiments, the at least one fluid passageway has first andsecond openings adjacent first and second ends of the prosthetic heartvalve, respectively. When the prosthetic valve is mounted on the balloonin a crimped state, the inflation fluid in the balloon can flow from afirst region of the balloon proximal to the first end of the prostheticvalve, inwardly through the first opening, through the fluid passageway,outwardly through the second opening and into a second region of theballoon distal to the second end of the prosthetic valve.

Another exemplary delivery apparatus for implantation of a prostheticdevice (e.g., a prosthetic heart valve) in the heart comprises a handleportion and an elongated shaft extending from the handle portion. Theshaft comprises a proximal end portion coupled to the handle portion anda distal end portion configured to mount a prosthetic heart valve in aradially compressed state. The apparatus also comprises a sliding memberdisposed on the proximal end portion of the shaft. The handle portioncomprising a rotatable member that is operatively coupled to the slidingmember so as to cause translational movement of the sliding member uponrotation of the rotatable member. A shaft engagement member is disposedon the shaft and couples the shaft to the sliding member. The shaftengagement member is configured to be manipulated between a first stateand a second state. In the first state, the shaft can move freely in thelongitudinal direction relative to the sliding member and the rotatablemember. In the second state, the shaft engagement member frictionallyengages the shaft and prevents rotational and longitudinal movement ofthe shaft relative to the sliding member such that rotation of therotatable member causes corresponding longitudinal movement of thesliding member and the shaft. When a prosthetic device is mounted on thedistal end of the shaft and the shaft engagement member is manipulatedto engage the shaft, the rotatable member can be used to adjust thelocation of the prosthetic device relative to its desired implantationlocation within the heart.

In some embodiments, the shaft engagement member comprises a colletdisposed on the shaft. The collet can have flexible fingers that can beforced to frictionally engage and retain the shaft relative to thesliding member so that the rotatable member can be used to adjust theposition of the prosthetic device mounted on the distal end portion ofthe shaft.

Another exemplary delivery device for implantation of a prostheticdevice (e.g., a prosthetic heart valve) within the heart, such as via atransapical or transaortic route, comprises an inflatable balloon, aproximal stop, and a distal stop. The stops are configured to limitlongitudinal movement of the prosthetic device relative to the balloonwhile the prosthetic device is mounted over the balloon in the radiallycompressed state between the proximal stop and the distal stop. Theproximal stop and the distal stop each comprise an end portionpositioned within the balloon and configured to be positioned adjacentthe prosthetic device when the prosthetic device is radially compressedbetween the proximal and distal stops. Each of the stop end portionscomprises at least one longitudinally extending slot that allows therespective stop end portion to be radially compressed to a smallerdiameter. The at least one longitudinally extending slot in each stopend portion can also be configured to allow a balloon-inflation fluid toflow radially through the respective stop and into the region of theballoon extending through the prosthetic valve.

In some embodiments, when a prosthetic device is mounted on the deliverydevice in the radially compressed state, the proximal stop and thedistal stop are configured to allow a balloon-inflation fluid to flowfrom a proximal portion of the balloon, through the at least one slot inthe proximal stop, through an intermediate portion of the balloonpositioned within the prosthetic device, through the at least one slotin the distal stop, and into a distal portion of the balloon.

In some embodiments, a proximal end of the balloon is attached to theproximal stop and a distal end of the balloon is attached to the distalstop.

In some embodiments, the delivery device further comprises an outershaft having a lumen and an inner shaft extending through the lumen ofthe outer shaft, with the proximal stop attached to a distal end of theouter shaft and positioned around the inner shaft and the distal stopattached to an outer surface of the inner shaft.

In some embodiments, the proximal stop further comprises a proximalportion attached to the distal end of the outer shaft and to a proximalend of the balloon, and an intermediate portion extending between theproximal portion and the end portion, the intermediate portion having anouter diameter that is less than an outer diameter of the proximalportion and less than the diameter of the end portion.

In some embodiments, the proximal stop is attached to the distal end ofthe outer shaft and further comprises at least one fluid passageway thatallows an inflation fluid to flow through the at least one passagewayand into the balloon.

In some embodiments, the distal stop further comprises a distal portionattached to a distal end of the balloon and an intermediate portionextending between the distal portion and the end portion, theintermediate portion having an outer diameter that is less than an outerdiameter of the distal portion and less than the diameter of the endportion.

In some embodiments, the end portion of each stop decreases in diameterin a direction extending away from the prosthetic device.

In some embodiments, the delivery device further comprises a noseconeattached to a distal end of the distal stop.

In some embodiments, at least one of the stop end portions comprises atleast three longitudinal slots that allow the stop end portion to beradially compressed to a smaller diameter when the prosthetic device iscrimped onto the delivery device.

An exemplary method of implanting a prosthetic heart valve within theheart comprises: (a) introducing a distal end portion of a deliverydevice into the native aortic valve of the heart, a distal end portionof the delivery device comprising an inflatable balloon, a proximal stopand a distal stop positioned at least partially within the balloon, anda radially expandable prosthetic heart valve mounted over the balloonand between the proximal stop and the distal stop in a radiallycompressed state; (b) inflating the balloon to radially expand theprosthetic heart valve within the native aortic valve, wherein theballoon is inflated with an inflation fluid that flows radially throughthe proximal and distal stops; (c) deflating the balloon; and (d)retracting the delivery device from the heart.

In some embodiments, the proximal stop is positioned adjacent to aproximal end of the prosthetic heart valve and the distal stop ispositioned adjacent to a distal end of the prosthetic heart valve, suchthat the prosthetic device is longitudinally contained between theproximal and distal stops during introduction of the prosthetic heartvalve through an introducer sheath into the body.

In some embodiments, inflating the balloon comprises causing theinflation fluid to flow: (i) through a first passageway in the proximalstop and into a proximal portion of the balloon; (ii) from the proximalportion of the balloon, through a second passageway in the proximalstop, and into an intermediate portion of the balloon within theprosthetic device; and (iii) from the intermediate portion of theballoon, through a passageway in the distal stop, and into a distalportion of the balloon.

In some embodiments, prior to introducing the delivery device into theheart, the prosthetic heart valve is crimped to the radially compressedstate onto delivery device while the proximal stop and the distal stopare simultaneously radially compressed. The prosthetic heart valve canhave a first outer diameter in the radially compressed state and theproximal stop and distal stop can be compressed from a second outerdiameter to about the first outer diameter during the crimping. Whencompressive pressure is released after the crimping, the proximal stopand distal stop can be configured to resiliently expand from about thefirst outer diameter to about the second outer diameter.

An exemplary system for delivering a prosthetic device into a patientcomprises an introducer sheath configured to be inserted partially intoa patient, a loader configured to be inserted into a proximal end theintroducer sheath, and a delivery device configured to be passed throughthe loader and the introducer sheath into the patient carrying aprosthetic device to be implanted in the patient. The loader comprises aflush port for selectively introducing fluid into the loader and a bleedport for selectively releasing fluid from within the loader, and boththe flush port and the bleed port are sealed with the same resilientlyflexible annular sealing member. The sealing member can comprise a pushtab that extends radially through the bleed port, such that the bleedport is configured to be selectively opened by depressing the push tabin the radially inward direction.

The foregoing and other objects, features, and advantages of theinvention will become more apparent from the following detaileddescription, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a delivery apparatus for implanting aprosthetic heart valve, according to one embodiment.

FIG. 2A is a cross-sectional view of the handle of the deliveryapparatus of FIG. 1.

FIG. 2B is another cross-sectional view of the handle of the deliveryapparatus of FIG. 1.

FIG. 3 is side view of a section of the handle and a section of thedistal end portion of the delivery apparatus of FIG. 1.

FIG. 4 is a side view of the distal end portion of the deliveryapparatus of FIG. 1.

FIG. 5 is a side view of the distal end portion of the deliveryapparatus of FIG. 1 showing the balloon in an inflated state.

FIG. 6 is an enlarged perspective view of a collet used in the handle ofthe delivery apparatus of FIG. 1.

FIG. 7 is a cross-sectional view of the collet of FIG. 6.

FIG. 8 is an enlarged side view of a mounting member for a prostheticheart valve.

FIGS. 9-11 are enlarged, cross-sectional views of the distal end portionof the delivery apparatus of FIG. 1, showing the inflation of a balloonfor deployment of a prosthetic heart valve on the balloon.

FIG. 12 is a perspective view of an alternative embodiment of a mountingmember for a prosthetic heart valve.

FIG. 13 is a side view of the mounting member of FIG. 12 shown partiallyin section.

FIG. 14 is an end view of the mounting member of FIG. 12.

FIGS. 15-17 are enlarged, cross-sectional views of the distal endportion of a delivery apparatus containing the mounting member of FIG.12, and showing the inflation of a balloon for deployment of aprosthetic heart valve on the balloon.

FIG. 18 is an exploded perspective view of the handle of a deliveryapparatus, according to another embodiment.

FIG. 19 is an enlarged perspective view of the collet, pusher element,spring, ring, and washer of the handle shown in FIG. 18.

FIG. 20 is a cross-sectional view of the handle of the deliveryapparatus of FIG. 18.

FIG. 21 is another cross-sectional view of the handle of the deliveryapparatus of FIG. 18.

FIG. 22 is a perspective view of the inner shaft, or slider, of thehandle shown in FIG. 18.

FIG. 23 is an enlarged side view of the inner nut of the handle shown inFIG. 18.

FIG. 24 is an enlarged cross-sectional view of the inner nut shown inFIG. 23.

FIGS. 25-27 are enlarged top, perspective and end views, respectively,of the rotatable knob of the handle shown in FIG. 18.

FIG. 28 is an enlarged perspective view of the indicator ring of thehandle shown in FIG. 18.

FIGS. 29-31 are cross-sectional views of the distal end portion of adelivery apparatus for a prosthetic heart valve, according to anotherembodiment, having two inflatable balloons for deploying a prostheticvalve.

FIG. 32 is a side view of a delivery apparatus for a prosthetic heartvalve, an introducer, and a loader device, according to anotherembodiment.

FIG. 33 is an enlarged, cross-sectional view of the distal end portionof the delivery apparatus of FIG. 32.

FIG. 34 is a cross-sectional view of the introducer of FIG. 32.

FIG. 35 is a cross-sectional view of the loader of FIG. 32.

FIG. 36 is a perspective view of the handle of the delivery apparatusshown in FIG. 32.

FIG. 37 is a partially exploded, perspective view of the handle of FIG.36.

FIG. 38 is a perspective view of the handle of FIG. 36, shown with aportion of the outer housing cut away for purposes of illustration.

FIG. 39 is an exploded, perspective view of the handle of FIG. 36.

FIG. 40 is a perspective view of another embodiment of a handle that canbe used in the delivery apparatus of FIG. 32.

FIG. 41 is a perspective of the handle of FIG. 40, with a portion of theouter housing and some internal components removed for purposes ofillustration.

FIG. 42 is an exploded, perspective view of the handle of FIG. 40.

FIG. 43 is a perspective view of another embodiment of a handle that canbe used in the delivery apparatus of FIG. 32.

FIG. 44 is a perspective of the handle of FIG. 43, with a portion of theouter housing and some internal components removed for purposes ofillustration.

FIG. 45 is an exploded, perspective view of the handle of FIG. 43.

FIG. 46 is a perspective view of a delivery apparatus for a prostheticheart valve, according to another embodiment.

FIG. 47 is an enlarged, cross-sectional view of the distal end portionof the delivery apparatus of FIG. 46.

FIG. 47A is an enlarged, cross-sectional view of the distal end portionof the delivery apparatus of FIG. 46 showing a prosthetic heart valvemounted in a crimped state on the balloon of the delivery apparatus.

FIG. 48 is a perspective view of the handle of the delivery apparatus ofFIG. 46, with a portion of the outer housing removed for purposes ofillustration.

FIG. 49 is a perspective view of an introducer, according to anotherembodiment.

FIG. 50 is an enlarged, cross-sectional view of the proximal housingportion of the introducer shown in FIG. 49.

FIG. 51 is a perspective view of a loader, according to anotherembodiment.

FIG. 52 is a cross-sectional view of the loader shown in FIG. 51.

FIG. 53 is a perspective view of the loader of FIG. 51 shown insertedinto the introducer of FIG. 49.

FIG. 54 is a perspective view of the button valve of the loader shown inFIG. 51.

FIG. 55 is a top plan view of the button valve shown in FIG. 51.

FIG. 56 is a perspective view of a prosthetic heart valve, according toone embodiment.

FIG. 57 is a side elevation view of the prosthetic heart valve of FIG.56.

DETAILED DESCRIPTION

In particular embodiments, a delivery apparatus for implanting aprosthetic, transcatheter heart valve via a patient's vasculatureincludes an adjustment device for adjusting the position of a balloonrelative to a crimped prosthetic valve (and/or vice versa). A ballooncatheter can extend coaxially with a guide (or flex) catheter, and aballoon member at the distal end of the balloon catheter can bepositioned proximal or distal to a crimped prosthetic valve. Asdescribed below in more detail, the balloon member and the crimpedprosthetic valve can enter the vasculature of a patient through anintroducer sheath and, once the balloon member and the crimpedprosthetic valve reach a suitable location in the body, the relativeposition of the prosthetic valve and balloon member can be adjusted sothat the balloon member is positioned within the frame of the prostheticvalve so that the prosthetic valve eventually can be expanded at thetreatment site. Once the crimped prosthetic valve is positioned on theballoon, the prosthetic valve is advanced to the vicinity of thedeployment location (i.e., the native aortic valve) and the adjustmentdevice can further be used to accurately adjust or “fine tune” theposition of the prosthetic valve relative to the desired deploymentlocation.

FIG. 1 shows a delivery apparatus 10 adapted to deliver a prostheticheart valve 12 (shown schematically in FIGS. 9-11) (e.g., a prostheticaortic valve) to a heart, according to one embodiment. The apparatus 10generally includes a steerable guide catheter 14 (FIG. 3), and a ballooncatheter 16 extending through the guide catheter 14. The guide cathetercan also be referred to as a flex catheter or a main catheter. The useof the term main catheter should be understood, however, to include flexor guide catheters, as well as other catheters that do not have theability to flex or guide through a patient's vasculature.

The guide catheter 14 and the balloon catheter 16 in the illustratedembodiment are adapted to slide longitudinally relative to each other tofacilitate delivery and positioning of prosthetic valve 12 at animplantation site in a patient's body, as described in detail below.

The guide catheter 14 includes a handle portion 20 and an elongatedguide tube, or shaft, 22 extending from handle portion 20 (FIG. 3). FIG.1 shows the delivery apparatus without the guide catheter shaft 22 forpurposes of illustration. FIG. 3 shows the guide catheter shaft 22extending from the handle portion 20 over the balloon catheter. Theballoon catheter 16 includes a proximal portion 24 (FIG. 1) adjacenthandle portion 20 and an elongated shaft 26 that extends from theproximal portion 24 and through handle portion 20 and guide tube 22. Thehandle portion 20 can include a side arm 27 having an internal passagewhich fluidly communicates with a lumen defined by the handle portion20.

An inflatable balloon 28 is mounted at the distal end of ballooncatheter 16. As shown in FIG. 4, the delivery apparatus 10 is configuredto mount the prosthetic valve 12 in a crimped state proximal to theballoon 28 for insertion of the delivery apparatus and prosthetic valveinto a patient's vasculature, which is described in detail in U.S.Publication No. 2009/0281619 (U.S. application Ser. No. 12/247,846,filed Oct. 8, 2008), which is incorporated herein by reference. Becauseprosthetic valve 12 is crimped at a location different from the locationof balloon 28 (e.g., in this case prosthetic valve 12 desirably iscrimped proximal to balloon 28), prosthetic valve 12 can be crimped to alower profile than would be possible if prosthetic valve 12 was crimpedon top of balloon 28. This lower profile permits the surgeon to moreeasily navigate the delivery apparatus (including crimped valve 12)through a patient's vasculature to the treatment location. The lowerprofile of the crimped prosthetic valve is particularly helpful whennavigating through portions of the patient's vasculature which areparticularly narrow, such as the iliac artery. The lower profile alsoallows for treatment of a wider population of patients, with enhancedsafety.

A nose piece 32 (FIG. 4) can be mounted at the distal end of thedelivery apparatus 10 to facilitate advancement of the deliveryapparatus 10 through the patient's vasculature to the implantation site.In some instances, it may be useful to have nose piece 32 connected to aseparate elongated shaft so that nose piece 32 can move independently ofother elements of delivery apparatus 10. Nose piece 32 can be formed ofa variety of materials, including various plastic materials.

As can be seen in FIG. 5, the balloon catheter 16 in the illustratedconfiguration further includes an inner shaft 34 (FIG. 2A) that extendsfrom proximal portion 24 and coaxially through the outer ballooncatheter shaft 26 and the balloon 28. The balloon 28 can be supported ona distal end portion of inner shaft 34 that extends outwardly from theouter shaft 26 with a proximal end portion 36 of the balloon secured tothe distal end of outer shaft 26 (e.g., with a suitable adhesive) (FIG.5). The outer diameter of inner shaft 34 is sized such that an annularspace is defined between the inner and outer shafts along the entirelength of the outer shaft. The proximal portion 24 of the ballooncatheter can be formed with a fluid passageway (not shown) that isfluidly connectable to a fluid source (e.g., saline) for inflating theballoon. The fluid passageway is in fluid communication with the annularspace between inner shaft 34 and outer shaft 26 such that fluid from thefluid source can flow through fluid passageway, through the spacebetween the shafts, and into balloon 28 to inflate the same and deployprosthetic valve 12.

The proximal portion 24 also defines an inner lumen that is incommunication with a lumen 38 of the inner shaft 34 that is sized toreceive guide wire (not shown) that can extend coaxially through theinner shaft 34 and the nose cone 32.

The inner shaft 34 and outer shaft 26 of the balloon catheter can beformed from any of various suitable materials, such as nylon, braidedstainless steel wires, or a polyether block amide (commerciallyavailable as Pebax®). The shafts 26, 34 can have longitudinal sectionsformed from different materials in order to vary the flexibility of theshafts along their lengths. The inner shaft 34 can have an inner lineror layer formed of Teflon® to minimize sliding friction with a guidewire.

The distal end portion of the guide catheter shaft 22 comprises asteerable section 68 (FIG. 3), the curvature of which can be adjusted bythe operator to assist in guiding the apparatus through the patient'svasculature, and in particular, the aortic arch. The handle 20 in theillustrated embodiment comprises a distal handle portion 46 and aproximal handle portion 48. The distal handle portion 46 functions as amechanism for adjusting the curvature of the distal end portion of theguide catheter shaft 22 and as a flex indicating device that allows auser to measure the relative amount of flex of the distal end of theguide catheter shaft 22. In addition, the flex indicating deviceprovides a visual and tactile response at the handle the device, whichprovides a surgeon with an immediate and direct way to determine theamount of flex of the distal end of the catheter.

The distal handle portion 46 can be operatively connected to thesteerable section 68 and functions as an adjustment mechanism to permitoperator adjustment of the curvature of the steerable section via manualadjustment of the handle portion. Explaining further, the handle portion46 comprises a flex activating member 50, an indicator pin 52, and acylindrical main body, or housing 54. As shown in FIGS. 2A and 2B, theflex activating member 50 comprises an adjustment knob 56 and a shaft 58extending proximally from the knob into the housing 54. A proximal endportion of the guide catheter shaft 22 extends into and is fixed withinthe central lumen of the housing 54. An inner sleeve 70 surrounds aportion of the guide catheter shaft 22 inside the housing 54. A threadedslide nut 72 is disposed on and is slidable relative to the sleeve 70.The slide nut 72 is formed with external threads that mate with internalthreads 60 of the shaft 58.

The slide nut 72 can be formed with two slots formed on the innersurface of the nut and extending the length thereof. The sleeve 70 canbe formed with longitudinally extending slots that are aligned with theslots of the slide nut 72 when the slide nut is placed on the sleeve.Disposed in each slot is a respective elongated nut guide, which can bein the form of an elongated rod or pin 76. The nut guides 76 extendradially into respective slots in the slide nut 72 to prevent rotationof the slide nut 72 relative to the sleeve 70. By virtue of thisarrangement, rotation of the adjustment knob 56 (either clockwise orcounterclockwise) causes the slide nut 72 to move longitudinallyrelative to the sleeve 70 in the directions indicated by double-headedarrow 74.

One or more pull wires 78 (FIG. 2A) couple the adjustment knob 56 to thesteerable section 68 to adjust the curvature of the steerable sectionupon rotation of the adjustment knob. For example, the proximal endportion of the pull wire 78 can extend into and can be secured to aretaining pin, such as by crimping the pin around the proximal end ofthe pull wire, which pin is disposed in a slot in the slide nut 72. Thepull wire extends from the pin, through the slot in the slide nut, aslot in the sleeve 70, and into and through a pull wire lumen in theshaft 22. The distal end portion of the pull wire is secured to thedistal end portion of the steerable section 68.

The pin, which retains the proximal end of the pull wire 78, is capturedin the slot in the slide nut 72. Hence, when the adjustment knob 56 isrotated to move the slide nut 72 in the proximal direction, the pullwire also is moved in the proximal direction. The pull wire pulls thedistal end of the steerable section 68 back toward the handle portion,thereby bending the steerable section and reducing its radius ofcurvature. The friction between the adjustment knob 56 and the slide nut72 is sufficient to hold the pull wire taut, thus preserving the shapeof the bend in the steerable section if the operator releases theadjustment knob 56. When the adjustment knob 56 is rotated in theopposite direction to move the slide nut 72 in the distal direction,tension in the pull wire is released. The resiliency of the steerablesection 68 causes the steerable to return its normal, non-deflectedshape as tension on the pull wire is decreased. Because the pull wire isnot fixedly secured to the slide nut 72 (the pin can move within theslot in the nut), movement of the slide nut in the distal direction doesnot push on the end of the pull wire, causing it to buckle. Instead, thepin is allowed to float within the slot of the slide nut 72 when theknob 56 is adjusted to reduce tension in the pull wire, preventingbuckling of the pull wire.

In particular embodiments, the steerable section 68 in its non-deflectedshape is slightly curved and in its fully curved position, the steerablesection generally conforms to the shape of the aortic arch. In otherembodiments, the steerable section can be substantially straight in itsnon-deflected position.

The distal handle portion 46 can have other configurations that areadapted to adjust the curvature of the steerable section 68. One suchalternative handle configuration is shown in co-pending U.S. patentapplication Ser. No. 11/152,288 (published under Publication No.US2007/0005131), which is incorporated herein by reference in itsentirety. Additional details relating to the steerable section andhandle configuration discussed above can be found in U.S. patentapplication Ser. No. 11/852,977 (published as U.S. Publication No.US2008/0065011), which is incorporated herein by reference in itsentirety.

The shaft 58 also includes an externally threaded surface portion 62. Asshown in FIG. 2B, a base portion 64 of the indicator pin 52 mates withthe externally threaded surface portion 62 of the shaft 58. The shaft 58extends into the main body 54 and the indicator pin 52 is trappedbetween the externally threaded surface portion 62 and the main body 54,with a portion of the indicator pin 52 extending into a longitudinalslot 66 of the handle. As the knob 56 rotated to increase the curvatureof the distal end of the guide catheter shaft 22, the indicator pin 52tracks the external threaded portion 62 of the flex activating memberand moves in the proximal direction inside of the slot 66. The greaterthe amount of rotation of the knob 56, the further indicator pin 52moves towards the proximal end of the proximal handle portion 46.Conversely, rotating the knob 56 in the opposite direction decreases thecurvature of the distal end of the guide catheter shaft 22 (i.e.,straightens the guide catheter shaft) and causes corresponding movementof the indicator pin 52 toward the distal end of the distal handleportion 46.

The outer surface of the main body 54 of the distal handle portion 46can include visual indicia adjacent the slot 66 that indicate the amountof flex of the distal end of the guide catheter shaft 22, based on theposition of the indicator pin 52 relative to the visual indicia. Suchindicia can identify the amount of flex in any of a variety of manners.For example, the outer surface of the main body 54 can include a seriesof numbers (e.g., 0 to 10) adjacent the slot that indicate the amount ofcurvature of the guide catheter shaft 22 based on the position of theindicator pin 52 relative to the number scale.

As described above, when the delivery apparatus is introduced into thevasculature of the patient, a crimped prosthetic valve 12 is positionedproximal to the balloon 28 (FIG. 4). Prior to expansion of the balloon28 and deployment of prosthetic valve 12 at the treatment site, theprosthetic valve 12 is moved relative to the balloon (or vice versa) toposition the crimped prosthetic valve on the balloon for deploying(expanding) the prosthetic valve. As discussed below, the proximalhandle portion 48 serves as an adjustment device that can be used tomove the balloon 28 proximally into position within the frame ofprosthetic valve 12, and further to accurately position the balloon andthe prosthetic valve at the desired deployment location.

As shown in FIGS. 2A and 2B, the proximal handle portion 48 comprises anouter housing 80 and an adjustment mechanism 82. The adjustmentmechanism 82, which is configured to adjust the axial position of theballoon catheter shaft 26 relative to the guide catheter shaft 22,comprises an adjustment knob 84 and a shaft 86 extending distally intothe housing 80. Mounted within the housing 80 on the balloon cathetershaft 26 is an inner support 88, which in turn mounts an inner shaft 90(also referred to as a slider or sliding mechanism) (also shown in FIG.22). The inner shaft 90 has a distal end portion 92 formed with externalthreads that mate with internal threads 94 that extend along the innersurface of the adjustment mechanism 82. The inner shaft 90 furtherincludes a proximal end portion 96 that mounts a securement mechanism98, which is configured to retain the position of the balloon cathetershaft 26 relative to the proximal handle portion 48 for use of theadjustment mechanism 82, as further described below. The inner shaft 90can be coupled to the inner support 88 such that rotation of shaft 86causes the inner shaft 90 to move axially within the handle. Forexample, the inner support 88 can have an axially extending rod or railthat extends into slot formed in the inner surface of the inner shaft90. The rod or rail prevents rotation of the inner shaft 90 but allowsit to move axially upon rotation of the shaft 86.

The securement mechanism 98 includes internal threads that mate withexternal threads of the proximal end portion 96 of the inner shaft.Mounted within the proximal end portion 96 on the balloon catheter shaft26 is a pusher element 100 and a shaft engagement member in the form ofa collet 102. The collet 102 is configured to be manipulated by thesecurement mechanism between a first state in which collet allows theballoon catheter shaft to be moved freely in the longitudinal androtational directions and a second state in which the colletfrictionally engages the balloon catheter shaft and prevents rotationaland longitudinal movement of the balloon catheter shaft relative to theinner shaft 90, as further described below.

As best shown in FIGS. 6 and 7, the collet 102 comprises a distal endportion 104, an enlarged proximal end portion 106, and a lumen 108 thatreceives the balloon catheter shaft 26. A plurality of axiallyextending, circumferentially spaced slots 110 extend from the proximalend of the collet to a location on the distal end portion 104, therebyforming a plurality of flexible fingers 112. The proximal end portioncan be formed with a tapered end surface 114 that engages acorresponding tapered end surface of the pusher element 100 (FIG. 2A).

As noted above, the securement mechanism 98 is operable to restrainmovement of the balloon catheter shaft 26 (in the axial and rotationaldirections) relative to the proximal handle portion 48. Explainingfurther, the securement mechanism 98 is movable between a proximalposition (shown in FIGS. 2A and 2B) and a distal position closer to theadjacent end of the knob 84. In the proximal position, the collet 102applies little, if any, force against the balloon catheter shaft 26,which can slide freely relative to the collet 102, the entire handle 20,and the guide catheter shaft 22. When the securement mechanism 98 isrotated so as to move to its distal position closer to knob 84, thesecurement mechanism urges pusher element 100 against the proximal endof the collet 102. The tapered surface of the pusher element pushesagainst the corresponding tapered surface 114 of the collet, forcingfingers 112 radially inward against the outer surface of the ballooncatheter shaft 26. The holding force of the collet 102 against theballoon catheter shaft locks the balloon catheter shaft relative to theinner shaft 90. In the locked position, rotation of the adjustment knob84 causes the inner shaft 90 and the balloon catheter shaft 26 to moveaxially relative to the guide catheter shaft 22 (either in the proximalor distal direction, depending on the direction the knob 84 is rotated).

The adjustment knob 84 can be utilized to position the prosthetic valve12 on the balloon 28 and/or once the prosthetic valve 12 is on theballoon, to position the prosthetic valve and the balloon at the desireddeployment site within the native valve annulus. One specific method forimplanting the prosthetic valve 12 in the native aortic valve is asfollows. The prosthetic valve 12 initially can be crimped on a mountingregion 120 (FIGS. 4 and 5) of the balloon catheter shaft 26 immediatelyadjacent the proximal end of the balloon 28 or slightly overlapping theproximal end of the balloon. The proximal end of the prosthetic valvecan abut the distal end 122 of the guide catheter shaft 22 (FIG. 4),which keeps the prosthetic valve in place on the balloon catheter shaftas the delivery apparatus and prosthetic valve are inserted through anintroducer sheath. The prosthetic valve 12 can be delivered in atransfemoral procedure by first inserting an introducer sheath into thefemoral artery and pushing the delivery apparatus through the introducersheath into the patient's vasculature.

After the prosthetic valve 12 is advanced through the narrowest portionsof the patient's vasculature (e.g., the iliac artery), the prostheticvalve 12 can be moved onto the balloon 28. For example, a convenientlocation for moving the prosthetic valve onto the balloon is thedescending aorta. The prosthetic valve can be moved onto the balloon,for example, by holding the handle portion 46 steady (which retains theguide catheter shaft 22 in place), and moving the balloon catheter shaft26 in the proximal direction relative to the guide catheter shaft 22. Asthe balloon catheter shaft is moved in the proximal direction, thedistal end 122 of the guide catheter shaft pushes against the prostheticvalve, allowing the balloon 28 to be moved proximally through theprosthetic valve in order to center the prosthetic valve on the balloon,as depicted in FIG. 9. The balloon catheter shaft can include one ormore radiopaque markers to assist the user in positioning the prostheticvalve at the desired location on the balloon. The balloon catheter shaft26 can be moved in the proximal direction by simply sliding/pulling theballoon catheter shaft in the proximal direction if the securementmechanism 98 is not engaged to retain the shaft 26. For more precisecontrol of the shaft 26, the securement mechanism 98 can be engaged toretain the shaft 26, in which case the adjustment knob 84 is rotated toeffect movement of the shaft 26 and the balloon 28.

As shown in FIG. 5, the delivery apparatus can further include amounting member 124 secured to the outer surface of the shaft 34 withinthe balloon 28. The mounting member helps retain the prosthetic valve inplace on the balloon by facilitating the frictional engagement betweenthe prosthetic valve and the outer surface of the balloon. The mountingmember 124 helps retain the prosthetic valve in place for finalpositioning of the prosthetic valve at the deployment location,especially when crossing the native leaflets, which typically arecalcified and provide resistance against movement of the prostheticvalve. The nose cone 32 can include a proximal portion 126 inside theballoon to assist in positioning the prosthetic valve. The proximalportion 126 desirably comprises a tapered member that has a maximumdiameter at its proximal end adjacent the distal end of the prostheticvalve (FIG. 9) and tapers in a direction toward the distal end of thenosecone 32. The tapered member 126 serves as a transition sectionbetween the nosecone and the prosthetic valve as the prosthetic valve ispushed through the calcified native leaflets by shielding the distal endof the prosthetic valve from contacting the native leaflets. AlthoughFIG. 9 shows the prosthetic valve having a crimped diameter slightlylarger than the diameter of the tapered member 126 at its proximal end,the tapered member 126 can have a diameter at its proximal end that isthe same as or slightly larger than the diameter of the crimpedprosthetic valve, or at least the same as or slightly larger than thediameter of the metal frame of the crimped prosthetic valve.

As shown in FIG. 9, the prosthetic valve desirably is positioned on theballoon for deployment such that the distal end of the prosthetic valveis slightly spaced from the nose cone portion 126. When the prostheticvalve is positioned as shown in FIG. 9, the guide catheter shaft 22 canbe moved proximally relative to the balloon catheter shaft 26 so thatthe guide catheter shaft is not covering the inflatable portion of theballoon 28, and therefore will not interfere with inflation of theballoon.

As the prosthetic valve 12 is guided through the aortic arch and intothe ascending aorta, the curvature of the steerable section 68 can beadjusted (as explained in detail above) to help guide or steer theprosthetic valve through that portion of the vasculature. As theprosthetic valve is moved closer toward the deployment location withinthe aortic annulus, it becomes increasingly more difficult to controlthe precise location of the prosthetic valve by pushing or pulling thehandle portion 20 due to the curved section of the delivery apparatus.When pushing or pulling the handle portion 20, slack is removed from thecurved section of the delivery apparatus before the pushing/pullingforce is transferred to the distal end of the delivery apparatus.Consequently, the prosthetic valve tends to “jump” or move abruptly,making precise positioning of the prosthetic valve difficult.

For more accurate positioning of the prosthetic valve within the aorticannulus, the prosthetic valve 12 is placed as close as possible to itsfinal deployment location (e.g., within the aortic annulus such that aninflow end portion of the prosthetic valve is in the left ventricle andan outflow end portion of the prosthetic valve is in the aorta) bypushing/pulling the handle 20, and final positioning of the prostheticvalve is accomplished using the adjustment knob 84. To use theadjustment knob 84, the securement mechanism 98 is placed in its lockedposition, as described above. Then, the handle 20 is held steady (whichretains the guide catheter shaft 22 in place) while rotating theadjustment knob 84 to move the balloon catheter shaft 26, and thus theprosthetic valve, in the distal or proximal directions. For example,rotating the knob in a first direction (e.g., clockwise), moves theprosthetic valve proximally into the aorta, while rotating the knob in asecond, opposite direction (e.g., counterclockwise) advances theprosthetic valve distally toward the left ventricle. Advantageously,operation of the adjustment knob 84 is effective to move the prostheticvalve in a precise and controlled manner without sudden, abruptmovements as can happen when pushing or pulling the delivery apparatusfor final positioning.

When the prosthetic valve is at the deployment location, the balloon 28is inflated to expand the prosthetic valve 12 (as depicted in FIG. 11)so as to contact the native annulus. The expanded prosthetic valvebecomes anchored within the native aortic annulus by the radial outwardforce of the valve's frame against the surrounding tissue.

The mounting member 124 within the balloon is configured to allow theinflation fluid (e.g., saline) to flow unobstructed from the proximalend of the balloon to the distal end of the balloon. As best shown inFIG. 8, for example, the mounting member 124 comprises a coiled wire(e.g., a metal coil) having a first section 124 a, a second section 124b, a third section 124 c, a fourth section 124 d, and a fifth section124 e. When the prosthetic valve 12 is positioned on the balloon fordeployment, the second section 124 b is immediately adjacent theproximal end of the prosthetic valve and the fourth section 124 d isimmediately adjacent the distal end of the prosthetic valve. The firstand fifth sections 124 a, 124 e, respectively, which are at the proximaland distal ends of the mounting member, respectively, are secured to theballoon catheter shaft. The second, third, and fourth sections 124 b,124 c, and 124 d, respectively, are relatively larger in diameter thanthe first and fifth sections and are spaced radially from the outersurface of the balloon catheter shaft. As can be seen, the secondsection 124 b and the fourth section 124 d are formed with spacesbetween adjacent coils. The third section can be formed with smallerspaces (or no spaces) between adjacent coils to maximize the surfacearea available to retain the prosthetic valve on the balloon duringfinal positioning of the prosthetic valve at the deployment location.

Referring to FIG. 10, the spacing between coils of the second and fourthsections 124 b, 124 d allows the inflation fluid to flow radiallyinwardly through the coils of the second section 124 b, axially throughthe lumen of the third section 124 c, radially outwardly through thecoils of the fourth section 124 d, into the distal section of theballoon, in the direction of arrows 128. The nose cone portion 126 alsocan be formed with one or more slots 130 that allow the inflation fluidto flow more easily past the proximal nose cone portion 126 into thedistal section of the balloon. In the illustrated embodiment, theproximal nose cone portion 126 has three circumferentially spaced slots130. Since the inflation fluid can pressurize and inflate the proximaland distal sections of the balloon at substantially the same rate, theballoon can be inflated more evenly for controlled, even expansion ofthe prosthetic valve.

FIGS. 12-14 illustrate a mounting member 140 according to anotherembodiment. The mounting member 140 comprises a cylindrical inner wall142, a cylindrical outer wall 144, and a plurality of angularly spacedribs 146 separating the inner and outer walls. The inner wall 142 issecured to the outer surface of the shaft 34 within the balloon. Inparticular embodiments, the mounting member 140 can be made of arelatively rigid material (e.g., polyurethane or another suitableplastic) that does not radially compress when the prosthetic valve ismoved onto the balloon. As shown in FIG. 16, during inflation of theballoon, inflation fluid in the proximal section of the balloon can flowthrough the spaces 148 between the inner and outer walls of the mountingmember, through one or more slots 130 in the proximal nose cone portion126, and into the distal section of the balloon, in the direction ofarrows 128.

It should be noted that the location of the threaded portions of theadjustment mechanism 82 and the inner shaft 90 can be reversed. That is,adjustment mechanism 82 can have an externally threaded portion thatengages an internally threaded portion of the inner shaft 90. Inaddition, for embodiments where the balloon 28 is initially positionedproximal to the prosthetic valve 12, the adjustment mechanism 82 can beused to move the balloon distally relative to the crimped prostheticvalve in order to center the prosthetic valve on the balloon fordeployment.

FIGS. 56 and 57 show a prosthetic heart valve 700, according to anotherembodiment. The heart valve 700 comprises a frame, or stent, 702 and aleaflet structure 704 supported by the frame. In particular embodiments,the heart valve 700 is adapted to be implanted in the native aorticvalve and can be implanted in the body using, for example, the deliveryapparatus 10 described above. The prosthetic valve 700 can also beimplanted within the body using any of the other delivery apparatusesdescribed herein. Thus, the frame 702 typically comprises a plasticallyexpandable material, such as stainless steel, a nickel based alloy(e.g., a nickel-cobalt-chromium alloy), polymers, or combinationsthereof. In other embodiments, the prosthetic valve 12, 700 can be aself-expandable prosthetic valve with a frame made from a self-expandingmaterial, such as Nitinol. When the prosthetic valve is a self-expandingvalve, the balloon of the delivery apparatus can be replaced with asheath or similar restraining device that retains the prosthetic valvein a radially compressed state for delivery through the body. When theprosthetic valve is at the implantation location, the prosthetic valvecan be released from the sheath, and therefore allowed to expand to itsfunctional size. It should be noted that any of the delivery apparatusesdisclosed herein can be adapted for use with a self-expanding valve.

FIG. 18 is an exploded, perspective view of the distal end section of analternative embodiment of a delivery device, indicated at 10′. Thedelivery device 10′ shares many similarities with the delivery device10, and therefore components of the delivery device 10′ that are thesame as those in the delivery device 10 are given the same referencenumerals and are not described further. One difference between thedelivery device 10 and the delivery device 10′ is that the latterincludes a different mechanism for locking/securing the balloon cathetershaft 26 relative to the adjustment knob 84.

Referring to FIGS. 18 and 19, the locking mechanism for the ballooncatheter shaft comprises an adjustment knob 150 housing an inner nut152, a washer 154 and a ring 156 disposed inside the inner nut 152, abiasing member in the form of a coiled spring 158, a pusher element 160,and a shaft engagement member in the form of a collet 102. As best shownin FIGS. 20 and 21, the inner nut 152 includes inner threads 162 (FIG.24) that engage the external threads of the distal end portion 96 of theinner shaft 90 (FIG. 22). The pusher element 160 includes a proximalshaft 164 and an enlarged distal end portion 166 that bears against theproximal end portion 106 of the collet 102. The spring 158 is disposedon the shaft 164 of the pusher element 160 and has a proximal end thatbears against the ring 156 and a distal end that bears against thedistal end portion 166 of the pusher element 160.

Referring to FIGS. 25-27, the adjustment knob 150 is formed with aplurality of longitudinally extending, circumferentially spacedprojections 168 on the inner surface of the knob. A distal portion ofthe knob 150 includes one or more radially extending projections 170 forgripping by a user and a proximal portion of the knob comprises asemi-annular portion 172. The knob 150 extends co-axially over the innernut 152 with the projections 168 mating with respective grooves 174 onthe outer surface of the nut 152 such that rotation of the knob causescorresponding rotation of the nut 152.

The delivery device 10′ can be used in the manner described above inconnection with the delivery device 10 to deliver a prosthetic valve inthe vicinity of the implantation site. To restrain movement of theballoon catheter shaft 26 for fine positioning of the prosthetic valve,the knob 150 is rotated, which in turn causes rotation of the inner nut152. The inner nut 152 is caused to translate in the distal directionalong the external threads on the distal end portion 96 of the shaft 90.As the nut 152 is moved distally, the nut 152 pushes against the ring156, which in turn pushes against the spring 158. The spring 158 pressesagainst the distal end portion 166 of the pusher element 160, urging thepusher element against the collet 102. The pushing force of the pusherelement 160 against the collet causes the fingers 112 of the collet tofrictionally engage the balloon catheter shaft 26, thereby retaining theballoon catheter shaft relative to the inner shaft 90. In the lockedposition, rotation of the adjustment knob 84 causes the inner shaft 90and the balloon catheter shaft 26 to move axially relative to the guidecatheter shaft 22 (either in the proximal or distal direction, dependingon the direction the knob 84 is rotated).

The biasing force of the spring 158 desirably is sufficient to lock thecollet against the balloon catheter shaft with a relatively small degreeof rotation of the knob 150, such as less than 360 degrees rotation ofthe knob. In the illustrated embodiment, the knob 150 is rotated lessthan 180 degrees from an unlocked position (in which the collet does notretain the balloon catheter shaft) to a locked position (in which thecollet frictionally engages and retains the balloon catheter shaft).Conversely, rotating the knob 150 in the opposite direction from thelocked position to the unlocked position through the same degree ofrotation allows the spring 158 to release the biasing force against thepusher element and the collet so as to permit axial movement of theballoon catheter shaft relative to the collet.

As best shown in FIG. 21, an indicator ring 176 is disposed on the shaft90 adjacent the proximal end of the knob 84. The indicator ring 176 sitswithin the semi-annular wall 172 of the knob 150 and includes anindicator tab 178 that extends into the annular space between the ends180 (FIG. 27) of the semi-annular wall 172. As best shown in FIG. 25,the outer surface of the knob 150 can include visual indicia thatindicate whether the balloon catheter shaft 26 is in a locked staterelative to the adjustment knob 84. In the illustrated implementation,for example, a first indicia 182 a is located adjacent one end 180 ofthe semi-annular wall 172 and a second indicia 182 b is located adjacentthe other end 180 of the semi-annular wall 172. The first indicia 182 ais a graphical representation of a closed lock (indicating that theballoon catheter shaft is in a locked state) and the second indicia 182b is a graphical representation of an open lock (indicating that theballoon catheter shaft is in an unlocked state). However, it should beunderstood that the indicia can take various other forms (text and/orgraphics) to indicate the locked and unlocked states.

Since the indicator ring 176 is fixed rotationally relative to the knob150, the indicator tab 178 limits rotation of the knob 150 through anarc length defined by the annular space between the ends 180 of thesemi-annular wall 172 (about 170 degrees in the illustrated embodiment).When the knob 150 is rotated in a first direction (counterclockwise inthe illustrated example), the indicator tab 178 will contact the wallend 180 adjacent indicia 182 b and prevent further rotation of the knob150. In this position, the collet 102 does not frictionally engage theballoon catheter shaft 26, which can be moved freely relative to theproximal handle portion 48. When the knob 150 is rotated in a seconddirection (clockwise in the illustrated example), the indicator tab 178will contact the wall end 180 adjacent indicia 182 a and prevent furtherrotation of the knob 150. In this position, the collet 102 is caused tofrictionally engage the balloon catheter shaft in the manner describedabove to restrain axial and rotational movement of the balloon cathetershaft relative to the proximal handle portion 48.

FIGS. 29-31 show the distal end portion of a balloon catheter 200,according to another embodiment, that can be used to implant anintraluminal implant, such as a stent or a stented prosthetic valve. Thefeatures of the balloon catheter 200 can be implemented in the deliveryapparatuses disclosed herein (e.g., apparatus 10 of FIG. 1). In thefigures, a prosthetic valve is shown schematically and is identified byreference numeral 202. The balloon catheter 200 includes a ballooncatheter shaft 204. The proximal end of the shaft 204 is mounted to ahandle (not shown) and the distal end of the shaft mounts a balloonassembly 206.

The balloon assembly 206 comprises an inner balloon 208 disposed insidean outer balloon 210. The inner balloon 208 is shaped to controlexpansion of the prosthetic valve 202 while the outer balloon is shapedto define the final expanded shape of the prosthetic valve. For example,as shown in FIG. 30, the inner balloon 208 can have a “dog bone” shapewhen inflated, having bulbous end portions that taper inwardly to form agenerally cylindrical center portion of a reduced diameter. The shape ofthe inner balloon 208 helps maintain the position of the prostheticvalve relative to the balloon as the prosthetic valve is expanded due tothe larger end portions that restrict movement of the prosthetic valvein the axial directions. The distal end portion of the shaft 204 canhave openings to allow an inflation fluid to flow from the lumen of theshaft 204 into the inner balloon 208.

The inner balloon 208 can be formed with small pores or openings thatare sized to permit suitable inflation of the inner balloon and allowthe inflation fluid to flow outwardly into the space between the twoballoons to inflate the outer balloon, as indicated by arrows 212. Afterthe inner balloon is inflated, which partially expands the prostheticvalve 202 (FIG. 30), the inflation fluid begins inflating the outerballoon 210 (FIG. 31). Inflation of the outer balloon further expandsthe prosthetic valve 202 to its final desired shape (e.g., cylindricalas shown in FIG. 31) against the surrounding tissue. In such a two-stageexpansion of the prosthetic valve 202, the position of the prostheticvalve relative to the shaft 204 can be controlled due to the innerballoon, which limits axial movement of the prosthetic valve during itsinitial expansion.

In an alternative embodiment, in lieu of or in addition to the pores orholes in the inner balloon, the inner balloon can be configured to burstat a predetermined pressure (e.g., 1-5 bars) after it is inflated to adesired size. After the inner balloon ruptures, the inflation fluid canbegin inflating the outer balloon.

FIG. 32 discloses a delivery system 300, according to anotherembodiment, that can be used to implant an expandable prosthetic valve.The delivery system 300 is specifically adapted for use in introducing aprosthetic valve into a heart in a transapical procedure, which isdisclosed in co-pending application Ser. No. 12/835,555, filed Jul. 13,2010 (U.S. Publication No. 2011/0015729), which is incorporated hereinby reference. In a transapical procedure, a prosthetic valve isintroduced into the left ventricle through a surgical opening in theapex of the heart. The delivery system 300 similarly can be used forintroducing a prosthetic valve into a heart in a transaortic procedure.In a transaortic procedure, a prosthetic valve is introduced into theaorta through a surgical incision in the ascending aorta, such asthrough a partial J-sternotomy or right parasternal mini-thoracotomy,and then advanced through the ascending aorta toward heart.

The delivery system comprises a balloon catheter 302, an introducer 304,and a loader 306. The balloon catheter 302 comprises a handle 308, anouter flush shaft 310 extending from the handle, an articulating mainshaft 312 extending from the handle 308 coaxially through the outershaft 310, an inner shaft 313 extending from the handle coaxiallythrough the articulating shaft 312, an inflatable balloon 314 mounted onthe shaft 312, and a nose cone 316 mounted on the inner shaft 313 distalto the balloon.

As best shown in FIG. 33, a pusher element, or stop member, 318 ismounted on the shaft 312 within the proximal portion of the balloon andthe nose cone is formed with a stop member 320 that extends into thedistal portion of the balloon. The spacing between the distal end of thepusher element 318 and the proximal end of the stop member 320 definesan annular space sized to partially receive a prosthetic valve that iscrimped on the balloon. In use, the prosthetic valve is crimped onto theballoon between the pusher element 318 and the stop member 320 such thatthe proximal end of the prosthetic valve can abut the pusher element andthe distal end of the prosthetic valve can abut the stop member(depicted in the embodiment shown in FIG. 47A). In this manner, thesetwo elements assist in retaining the position of the prosthetic valve onthe balloon as it is inserted through the introducer 304.

As shown in FIG. 32, the introducer 304 comprises an introducer housing322 and a distal sheath 324 extending from the housing 322. Theintroducer 304 is used introduce or insert the balloon catheter 302 intoa patient's body. As shown in FIG. 34, the introducer housing 322 housesone or more valves 326 and includes a proximal cap 328 for mounting theloader. The loader 306 provides a coupling between the balloon catheterand the introducer. The loader 306 includes two retaining arms 330 thatengage the proximal cap 328 of the introducer. The manner of using aloader to assist in inserting a balloon catheter and prosthetic valveinto an introducer is described below with respect to the embodimentshown in FIGS. 51-53.

The construction of the handle 308 is shown in FIGS. 36-39. The handle308 includes a housing 332, which houses a mechanism for effectingcontrolled deflection, or articulation, of balloon catheter shaft 312.The mechanism in the illustrated embodiment comprises a shaft 334, asliding mechanism 336, a spring 338, and proximal and distal rack gears340, 342, respectively. The proximal end portion of the shaft 334 isformed with external threads that engage internal threads of twothreaded nuts 364 a, 364 b inside the handle. The shaft 334 can rotatewithin the handle but is restricted from translational movement withinthe handle. The nuts 364 desirably have opposite threads and aredisposed on respective portions of the shaft 334 that have correspondingexternal threads. For example, the proximal nut 364 a can haveleft-handed threads and is disposed on left-handed threads on the shaft,while the distal nut 364 b can have right-handed threads and is disposedon right-handed threads on the shaft. This causes the nuts 364 totranslate in opposite directions along the threads of the shaft 334 uponits rotation. As best shown in FIG. 39, each nut 364 has a pair ofradially extending flanges 380 on diametrically opposite sides of thenut. The inside of the housing is formed with a pair of elongated slots382 (one of which is shown in FIG. 39) on opposing inside surfaces ofthe housing. The opposing flanges 380 on each nut 364 can extend intorespective slots 382, which prevent rotation of the nuts upon rotationof the shaft 334. In this manner, the nuts 364 are caused to movelengthwise of the shaft 334 upon its rotation.

The distal end portion of the shaft 334 supports a proximal spur gear344, a distal spur gear 346, a proximal clutch 348, and a distal clutch350. The shaft 334 has a flat 366 that engages corresponding flats oncenter bores of the clutches 348, 350, which provides for rotation ofthe shaft when one of the clutches is engaged and rotated by arespective spur gear, as described below. The sliding mechanism 336includes a user-engageable actuator 352, an elongate arm 354 extendingfrom actuator 352, and proximal and distal rings 356, 358, respectively,mounted on the distal end portion of the arm 354. Mounted on the shaft334 and held between the rings is a coil spring 360.

Two pull wires (not shown) extend from the handle through the ballooncatheter shaft 312 on diametrically opposite sides of the ballooncatheter shaft to its distal end portion. A first pull wire has aproximal end secured to the proximal nut 364 a inside the handle and adistal end that is secured to the distal end portion of the ballooncatheter shaft 312. A second pull wire has a proximal end secured to thedistal nut 364 b inside the handle and a distal end that is secured tothe distal end portion of the balloon catheter shaft 312 on adiametrically opposite side from the securement location of the firstpull wire.

The housing 332 is configured to actuate the deflection (articulation)mechanism inside the handle when it is squeezed by the hand of a user.For example, the housing 332 can comprise a lower housing section 368and an upper housing section 370, which can be comprised of twoseparable housing sections 370 a, 370 b for ease of assembly. Referringto FIG. 36, the lower housing section 368 is mounted to the upperhousing section 370 in a manner that permits the two sections to movetoward and apart from each other a limited distance when squeezed by auser's hand, as indicated by arrow 374. The torsion spring 338 has onearm 376 a that bears against the inner surface of the upper housingportion 370 and another arm 376 b that bears against the inner surfaceof the lower housing portion 368 to resiliently urge the two housingportions apart from each other. As such, squeezing the handle moves theupper and lower housing portions together and releasing manual pressureallows the housing portions to move apart from each other a limitedamount under the spring force. In an alternative embodiment, a portionof the housing can be made of a flexible or deformable material that candeform when squeezed by the hand of a user in order to actuate thedeflection mechanism.

The deflection mechanism works in the following manner. Squeezing thehandle 332 causes the rack gears 340, 342 to move in opposite directionsperpendicular to shaft 334 (due to movement of the upper and lowerhousing sections), which in turn causes rotation of the correspondingspur gears 344, 346 in opposite directions. The sliding mechanism 336can be manually moved between a proximal position, a neutral(intermediate) position, and a distal position. When the slidingmechanism is in the neutral position (FIG. 36), the clutches aredisengaged from their respective spur gears, such that rotation of thespur gears does not rotate the shaft 334. However, sliding the slidingmechanism 336 distally to a distal position pushes the coil spring 360against the distal clutch 350 to engage the distal spur gear 346. Whilethe sliding mechanism is held in the distal position, the handle issqueezed and the resulting rotation of the distal spur gear 346 istransmitted to the shaft 334 to rotate in the same direction, which inturn causes the nuts 364 to move in opposite directions along the shaft334 (e.g., toward each other). Translation of the nuts 364 in oppositedirections applies tension to the first pull wire and introduces slackto the second pull wire, causing the balloon catheter shaft 312 to bendor deflect in a first direction. The face of the clutch 350 that engagesspur gear 346 is formed with teeth 362 that cooperate with correspondingfeatures of the gear to rotate the clutch and shaft 334 when the handleis squeezed, and allow the gear to spin or rotate relative to the clutchwhen manual pressure is removed from the handle. In this manner, theballoon catheter shaft bends a predetermined amount corresponding toeach squeeze of the handle. The deflection of the balloon catheter shaftcan be controlled by repeatedly squeezing the handle until the desireddegree of deflection is achieved.

The balloon catheter shaft 312 can be deflected in a second direction,opposite the first direction by sliding the sliding mechanism 336 in theproximal direction, which pushes the coil spring 360 against theproximal clutch 348 to engage the proximal spur gear 344. While holdingthe sliding mechanism in the proximal position and squeezing the handle,the proximal spur gear 344 rotates the proximal clutch 348 in the samedirection. Rotation of the proximal clutch is transmitted to the shaft334 to rotate in the same direction, resulting in translation of thenuts 364 in opposite directions (e.g., if the nuts move toward eachother when the sliding mechanism is in the distal position, then thenuts move away from each other when the sliding mechanism is in theproximal position). The proximal clutch 348 is similarly formed withteeth 362 that engage the proximal spur gear 344 and cause rotation ofthe proximal clutch and shaft 334 only when the handle is squeezed butnot when manually pressure is removed from the handle. In any case,movement of the threaded nuts 364 applies tension to the second pullwire and introduces slack to the first pull wire, causing the ballooncatheter shaft 312 to bend in the opposite direction.

FIGS. 40-42 show an alternative embodiment of a handle, indicated at400, that can be incorporated in the balloon catheter 302 (in place ofhandle 308). The handle 400 comprises a housing 402, which can be formedfrom two halves 402 a, 402 b for ease of assembly. Two wheels, orrotatable knobs, 404 a, 404 b are positioned on opposite sides of thehandle. The knobs are mounted on opposite ends of a shaft 406 havinggear teeth 408. A rotatable, hollow cylinder 410 extends lengthwiseinside of the handle in a direction perpendicular to shaft 406. Thecylinder 410 includes external gear teeth 412 that engage the gear teeth408 on shaft 406. The inner surface of the cylinder 410 is formed withinternal threads 414, which can include right-handed and left-handedthreads. A proximal threaded nut 416 a and a distal threaded nut 416 bare disposed inside of the cylinder 410 and are mounted for slidingmovement on a rail 418 that extends co-axially through the cylinder. Thenuts 416 a, 416 b have external threads that are threaded in oppositedirections and engage the corresponding right-handed and left-handedthreads on the inner surface of the cylinder 410. The rail 418 has aflat 420 that engages corresponding flats on the inner bores of the nuts416 a, 416 b, which allows the nuts to translate along the length of therail without rotating.

First and second pull wires (not shown) are provided and secured torespective nuts 416 a, 416 b and the distal end of the balloon cathetershaft 312 as previously described. Deflection of the balloon cathetershaft 312 in first and second opposing directions can be accomplished byrotating the knobs 404 a, 404 b (which rotate together) clockwise andcounterclockwise. For example, rotating the knobs clockwise producesrotation of the cylinder 410 via gear teeth 408 engaging gear teeth 412.Rotation of cylinder 410 causes the nuts 416 a, 416 b to move inopposite directions along the rail 418 (e.g., toward each other).Translation of the nuts in opposite directions applies tension to thefirst pull wire and introduces slack to the second pull wire, causingthe balloon catheter shaft 312 to bend or deflect in a first direction.Rotating the knobs counterclockwise produces rotation of the cylinder410 in a direction opposite its initial rotation mentioned above.Rotation of cylinder 410 causes the nuts 416 a, 416 b to move inopposite directions along the rail 418 (e.g., away each other).Translation of the nuts in opposite directions applies tension to thesecond pull wire and introduces slack to the first pull wire, causingthe balloon catheter shaft 312 to bend or deflect in a second direction,opposite the first direction.

The handle 400 can optional include a pusher actuation mechanism 422that is configured to move a pusher device adjacent the distal end ofthe balloon catheter. The pusher device extends partially over theballoon and holds the prosthetic valve in place on the balloon as theprosthetic valve and balloon catheter are inserted through theintroducer. A pusher device is disclosed in co-pending application Ser.No. 12/385,555, which is incorporated herein by reference. The actuationmechanism 422 is pivotably connected to a linkage arm 424, which in turnis pivotably connected to a proximal holder 426 of the pusher device(not shown). The pusher device can extend from the proximal holder 426to the balloon 314. Moving the actuation mechanism 422 to a distalposition moves the pusher device in a position partially extending overthe balloon 314 and holding the prosthetic valve in place on the balloonfor insertion through the introducer 304. Moving the actuation mechanism422 to a proximal position moves the pusher device proximally away fromthe balloon and the prosthetic valve once inside the heart so that theballoon can be inflated for deployment of the prosthetic valve. If amovable pusher device is not used (as in the illustrated ballooncatheter 302), then the pusher actuation mechanism 422 would not beneeded. For example, in lieu of or in addition to such a pusher device,stop members 318, 320 inside the balloon can be used to retain theposition of the prosthetic valve on the balloon (FIGS. 33 and 47A).

FIGS. 43-45 show another embodiment of a handle, indicated at 500, thatcan be incorporated in the balloon catheter 302 (in place of handle308). The handle 500 comprises a housing 502, which can be formed frommultiple housing sections, including first and second distal housingportions 504, 506, respectively, that form a distal housing space, andfirst and second proximal housing portions 508, 510, respectively, thatform a proximal housing space. The housing houses a proximal cylinder512 and a distal cylinder 514, which house proximal and distal nuts 516,518, respectively. The nuts are disposed on a rail 520 that extendsco-axially through the cylinders 512, 514. The cylinders 512, 514 haveopposing internal threads, e.g., the proximal cylinder can haveright-handed threads and the distal cylinder can have left-handedthreads. The cylinders 512, 514 are secured to each other end-to-end(e.g., with a frictional fit between the distal end of the proximalcylinder and the proximal end of the distal cylinder) so that bothrotate together. In other embodiments, the cylinders 512, 514 can beformed as a single cylinder having left-handed and right-handed threadsas used in the handle 400 described above.

A user-engageable, rotatable knob 522 is mounted on the outside of thehousing 502 and engages the proximal cylinder 512 (e.g., through anannular gap in the housing) such that rotation of the knob 522 causescorresponding rotation of the cylinders 512, 514. The deflectionmechanism of this embodiment works in a manner similar to that shown inFIGS. 40-42 to alternatively apply tension and introduce slack in firstand second pull wires (not shown) secured to the nuts 516, 518,respectively. For example, rotating the knob 522 in a first directioncauses the nuts to translate in opposite directions along the rail 520(e.g., toward each other), which is effective to apply tension to thefirst pull wire and introduce slack to the second pull wire, causing theballoon catheter shaft 312 to bend or deflect in a first direction.Rotating the knob 522 in a second direction causes the nuts to translatein opposite directions (e.g., away from each other), which is effectiveto apply tension to the second pull wire and introduce slack to thefirst pull wire, causing the balloon catheter shaft 312 to bend ordeflect in a second direction, opposite the first bending direction.

FIG. 46 discloses a delivery apparatus 600, according to anotherembodiment, that can be used to implant an expandable prosthetic heartvalve. The delivery apparatus 600 is specifically adapted for use inintroducing a prosthetic valve into a heart in a transapical ortransaortic procedure. A delivery system for implanting a prostheticheart valve can comprise the delivery apparatus 600, an introducer 602(FIGS. 49-50), and a loader 604 (FIGS. 51-52).

Referring to FIGS. 46-47, the delivery apparatus 600 in the illustratedform is a balloon catheter comprising a handle 606, a steerable shaft608 extending from the handle 606, an inner shaft 610 extending from thehandle 606 coaxially through the steerable shaft 608, an inflatableballoon 612 extending from the distal end of the steerable shaft 608, aproximal shoulder, or stop member, 614 extending from the distal end ofthe steerable shaft 608 into the proximal end region of the balloon, anose cone 616 mounted on the distal end of the inner shaft 610, and adistal shoulder, or stop member, 618 mounted on the inner shaft 610within the distal end region of the balloon. The distal stop member 618can be an integral extension of the nose cone 616 as shown. The proximalstop member 614 can have a proximal end portion 620 secured to theoutside surface of the distal end portion of the steerable shaft 608.The balloon 612 can have a proximal end portion 622 and a distal endportion 624, with the proximal end portion 622 being secured to theouter surfaces of the shaft 608 and/or the end portion 620 of theproximal stop 614 and the distal end portion 624 being secured to theouter surface of a distal end portion 626 of the distal stop member 618.

As best shown in FIG. 47, the proximal end portion 620 of the proximalstop member 614 includes one or more openings 646 for inflation fluidformed in the annular wall between the outer surface of the inner shaft610 and the inner surface of the outer shaft 608. The openings 646 allowinflation fluid to flow outwardly from the space between the inner shaft610 and the outer shaft 608 into the balloon in the distal direction.

The proximal stop member 614 has a distal end portion 628 in form of asubstantially cone-shaped member, and the distal stop member 618 has aproximal end portion 630 of the same shape. The spacing between thecone-shaped members 628, 630 defines an annular space sized to at leastpartially receive a prosthetic valve that is crimped on the balloon. Inuse, as shown in FIG. 47A, the prosthetic valve 12 is crimped onto theballoon between the cone-shaped members 628, 630 such that theprosthetic valve is retained on the balloon between the cone-shapedmembers as the prosthetic valve is advanced through the introducer.Desirably, the spacing between the cone-shaped members 628, 630 isselected such that the prosthetic valve is slightly wedged between thecone-shaped members with the non-inflated balloon extending between theproximal end of the prosthetic valve and the proximal member 628 andbetween the distal end of the prosthetic valve and the distal member630. In addition, the maximum diameter of the members 628, 630 at theirends adjacent the ends of the prosthetic valve desirably is about thesame as or slightly greater than the outer diameter of the frame of theprosthetic valve 12 when crimped onto the balloon.

As further shown in FIG. 47, each of the cone-shaped members 628, 630desirably is formed with one or more slots 632. In the illustratedembodiment, each of the cone-shaped members 628, 630 has three suchslots 632 that are equally angularly spaced in the circumferentialdirection. The slots 632 facilitate radial compression of thecone-shaped members 628, 630, which is advantageous during manufacturingof the delivery device and during crimping of the prosthetic valve. Inparticular, the proximal and distal ends 622, 624 of the balloon may berelatively smaller than the maximum diameter of the cone-shaped members628, 630. Thus, to facilitate insertion of the cone-shaped members 628,630 into the balloon during the assembly process, they can be radiallycompressed to a smaller diameter for insertion into the balloon and thenallowed to expand once inside the balloon. When the prosthetic valve iscrimped onto the balloon, the inside surfaces of the crimping device(such as the surfaces of crimping jaws) may contact the cone-shapedmembers 628, 630 and therefore will radially compress the cone-shapedmembers along with the prosthetic valve. Typically, the prosthetic valvewill undergo a small amount of recoil (radial expansion) once removedfrom the crimping device. Due to the compressibility cone-shaped members628, 630, the prosthetic valve can be fully compressed to a crimpedstate in which the metal frame of the prosthetic valve has an outerdiameter equal to or less than the maximum diameter of the cone-shapedmembers (accounting for recoil of the prosthetic valve).

The slots 632 in the cone-shaped members 628, 630 also allow inflationfluid to flow radially inwardly through the cone-shaped members andthrough the region of the balloon extending through the crimpedprosthetic valve in order to facilitate expansion of the balloon. Thus,inflation fluid can flow from a proximal region of the balloon, inwardlythough slots 632 in proximal stop member 628, through the region of theballoon extending through the prosthetic valve, outwardly through slots632 in distal stop 630, and into a distal region of the balloon. Anotheradvantage of the distal stop member 618 is that it serves a transitionregion between the nose cone and the prosthetic valve. Thus, when theprosthetic valve is advanced through the leaflets of a native valve, thedistal stop member 618 shields the distal end of the prosthetic valvefrom contacting the surrounding tissue, which can otherwise dislodge orprevent accurate positioning of the prosthetic valve prior todeployment.

The construction of the handle 606 is shown in FIG. 48. The handle 606comprises a housing 634, which can be formed from multiple housingsections. The housing 634 houses a mechanism for effecting controlledarticulation/deflection of the shaft 608. The mechanism in theillustrated embodiment comprises a threaded shaft 636, and a threadednut 638 disposed on the shaft. The proximal end portion of the shaft 636is formed with external threads that engage internal threads of thethreaded nut 638. The shaft 636 can rotate within the handle but isrestricted from translational movement within the handle. The nut 638has opposing flanges 640 (one of which is shown in FIG. 48), whichextend into respective slots formed on the inside surfaces of thehousing to prevent rotation of the nut. In this manner, the nut 638translates along the threads of the shaft 636 upon rotation of theshaft.

The distal end portion of the shaft 636 supports user-engageable,rotatable knob 642. The shaft 636 is coupled to the knob 12 such thatrotation of the knob causes corresponding rotation of the shaft 636. Apull wire 644 extends from the handle through the balloon catheter shaft608 on one side of the balloon catheter shaft to its distal end portion.The pull wire 644 has a proximal end secured to the threaded nut 638inside the handle and a distal end that is secured to the distal endportion of the balloon catheter shaft 608. The articulation mechanism ofthis embodiment works by rotating the knob 642 in one direction, whichcauses the threaded nut 638 to translate along the shaft 636, which iseffective to apply tension to the pull wire causing the balloon cathetershaft 608 to bend or articulate in a predetermined direction. Rotatingthe knob 642 in the opposite direction causes to the nut 638 totranslate in the opposite direction, thereby releasing tension in thepull wire, which allows the shaft 608 to deflect in the oppositedirection under its own resiliency. In alternative embodiments, anotherthreaded nut and respective pull wire can be provided in the housing toallow for bi-directional steering of the shaft 608, as described abovein connection with the embodiments of FIGS. 36-45.

FIG. 49 is a perspective view of the introducer 602, which comprises anintroducer housing assembly 650 and a sheath 652 extending from thehousing assembly 650. The introducer 602 is used to introduce or insertthe delivery apparatus 600 into a patient's body. In a transapicalprocedure, for example, the sheath 652 is inserted through surgicalincisions in the chest and the apex of the heart to position the distalend of the sheath in the left ventricle (such as when replacing thenative aortic valve). The introducer 602 serves as a port or entry pointfor inserting the delivery apparatus into the body with minimal bloodloss. As shown in FIG. 50, the introducer housing 650 houses one or morevalves 654, and includes a distal cap 656 to secure sheath 652 to thehousing 650 and a proximal cap 658 for mounting the loader 604.

FIGS. 51-52 are respective and cross-sectional views of the loader 604,which is used to protect the crimped prosthesis during insertion intothe introducer 602. The loader 604 in the illustrated configurationcomprises a distal loader assembly 660 and a proximal loader assembly662. The distal loader assembly 660 and proximal loader assembly 662 canbe secured to each other by mating female and male threads 680 and 682,respectively. The distal loader assembly 660 comprises a loader tube 664and a loader distal cap 666. The proximal loader assembly 662 comprisesa loader housing 668, a button valve 670, a washer 672, two disc valves674, and a proximal loader cap 676. The distal loader cap 666 can beformed with a lip 684 that is configured to engage the proximal cap 658of the introducer 602 as shown in FIG. 53.

In use, the proximal loader assembly 662 (apart from the distal loaderassembly 660) can be placed on the balloon catheter shaft 608 prior toplacing the prosthetic valve on the balloon and the crimping theprosthetic valve to avoid passing the crimped prosthetic valve throughthe sealing members 674 inside the housing 668. After the prostheticvalve is crimped onto the balloon, the distal loader assembly 660 isslid over the crimped prosthetic valve and secured to the proximalloader assembly 662 (by screwing threads 682 into threads 680). As shownin FIG. 53, the loader tube 664 (while covering the crimped prostheticvalve) can then be inserted into and through the introducer housing 650so as to extend through the internal sealing members 654 (FIG. 50). Theloader tube 664 therefore prevents direct contact between the sealingmembers 654 of the introducer and the crimped prosthetic valve. Theloader 604 can be secured to the introducer 602 by pressing the annularlip 684 of the loader into the proximal cap 658 of the introducer. Afterinsertion of the loader tube into the introducer, the prosthetic valvecan be advanced from the loader tube, through the sheath 652, and into aregion with the patient's body (e.g., the left ventricle).

As best shown in FIG. 53, the proximal cap 658 of the introducercomprises first and second diametrically opposed ribbed portions 694 andfirst and second diametrically opposed, deflectable engaging portions696 extending between respective ends of the ribbed portions. When theloader 604 is inserted into the introducer 602, the lip 684 of theloader snaps into place on the distal side of the engaging portions 696,which hold the loader in place relative to the introducer. In theirnon-deflected state, the ribbed portions 694 are spaced slightly fromthe adjacent surfaces of the cap 666 of the loader. To remove the loaderfrom the introducer, the ribbed portions 694 are pressed radiallyinwardly, which causes the engaging portions 696 to deflect outwardlybeyond the lip 684, allowing the loader and the introducer to beseparated from each other.

Fluid (e.g., saline) can be injected into the loader 604 through a luredport 678, which when pressurized by fluid will allow for fluid flow in asingle direction into the loader housing. Alternatively, fluid (e.g.,blood, air and/or saline) can be removed from the loader 604 bydepressing the crossed portion of the button valve 670, which creates anopening between the valve 670 and the loader housing. As best shown inFIGS. 52 and 54, the button 670 in the illustrated embodiment comprisesan elastomeric annular ring 686 and a user-engageable projection 688that extends outwardly through an opening 690 in the loader housing 668.The ring 686 seals the opening 690 and another opening 692 in the loaderhousing that communicates with the port 678. When a pressurized fluid isintroduced into the port 678, the pressure of the fluid causes theadjacent portion of the ring 686 to deflect inwardly and away from itsposition sealing opening 692, allowing the fluid to flow into theloader. Alternatively, to remove fluid from the loader, a user candepress projection 688, which causes the adjacent portion of the ring686 to deflect inwardly and away from its position sealing the opening690, allowing fluid in the loader to flow outwardly through the opening690.

General Considerations

For purposes of this description, certain aspects, advantages, and novelfeatures of the embodiments of this disclosure are described herein. Thedisclosed methods, apparatuses, and systems should not be construed aslimiting in any way. Instead, the present disclosure is directed towardall novel and nonobvious features and aspects of the various disclosedembodiments, alone and in various combinations and sub-combinations withone another. The methods, apparatuses, and systems are not limited toany specific aspect or feature or combination thereof, nor do thedisclosed embodiments require that any one or more specific advantagesbe present or problems be solved.

Although the operations of some of the disclosed methods are describedin a particular, sequential order for convenient presentation, it shouldbe understood that this manner of description encompasses rearrangement,unless a particular ordering is required by specific language. Forexample, operations described sequentially may in some cases berearranged or performed concurrently. Moreover, for the sake ofsimplicity, the attached figures may not show the various ways in whichthe disclosed methods can be used in conjunction with other methods. Asused herein, the terms “a”, “an” and “at least one” encompass one ormore of the specified element. That is, if two of a particular elementare present, one of these elements is also present and thus “an” elementis present. The terms “a plurality of” and “plural” mean two or more ofthe specified element.

As used herein, the term “and/or” used between the last two of a list ofelements means any one or more of the listed elements. For example, thephrase “A, B, and/or C” means “A,” “B,” “C,” “A and B,” “A and C,” “Band C” or “A, B and C.”

As used herein, the term “coupled” generally means physically coupled orlinked and does not exclude the presence of intermediate elementsbetween the coupled items absent specific contrary language.

In view of the many possible embodiments to which the principles of thedisclosed invention may be applied, it should be recognized that theillustrated embodiments are only preferred examples of the invention andshould not be taken as limiting the scope of the invention. Rather, thescope of the invention is defined by the following claims. We thereforeclaim as our invention all that comes within the scope and spirit ofthese claims.

We claim:
 1. A delivery apparatus for positioning a prosthetic heartvalve, comprising: a shaft having a proximal end portion, a distal endportion, a lumen extending from the proximal end portion to the distalend portion, and a plurality of openings formed in the distal endportion, wherein the shaft is configured such that a fluid can flowthrough the lumen and the openings; an inner balloon having end portionsand a center portion disposed between the end portions, wherein theinner balloon is mounted on the distal end portion of the shaft and isin fluid communication with the openings of the shaft, and wherein whenthe inner balloon is inflated with the fluid, the end portions expandfarther radially outwardly than the center portion; and an outer balloonmounted to the shaft and disposed over the inner balloon, wherein theouter balloon is configured to fully expand after the inner balloon atleast partially expands, wherein the inner balloon includes openingsthat are configured to allow at least some of the fluid to flow out ofthe inner balloon and into the outer balloon, and wherein the outerballoon is sealed so as to prevent fluid from flowing out of the outerballoon into a patient's vasculature.
 2. The delivery apparatus of claim1, wherein when the inner balloon is inflated with the fluid, the endportions of the inner balloon at least partially expand prior to theouter balloon fully expanding.
 3. The delivery apparatus of claim 1,wherein the inner balloon has a dog bone shape when inflated.
 4. Thedelivery apparatus of claim 3, wherein the outer balloon has acylindrical shape when fully inflated.
 5. The delivery apparatus ofclaim 1, wherein when the outer balloon is fully inflated, the outerballoon is radially spaced from the inner balloon.
 6. The deliveryapparatus of claim 1, wherein the inner balloon is configured to burstat a predetermined pressure, and wherein the outer balloon is configuredto fully expand after the inner balloon bursts.
 7. The deliveryapparatus of claim 6, wherein the predetermined pressure is 1-5 bar. 8.The delivery apparatus of claim 1, further comprising a handle coupledto the proximal end portion of the shaft, and wherein the deliveryapparatus is configured for a transfemoral delivery procedure.
 9. Anassembly, comprising: a prosthetic heart valve having a frame, a leafletstructure supported by the frame, an inflow end portion, an outflow endportion, and an intermediate portion disposed between the inflow endportion and the outflow end portion, wherein the prosthetic heart valveis radially expandable from a compressed state to an expanded state; anda delivery apparatus configured to radially expand the prosthetic heartvalve from the compressed state to the expanded state, wherein thedelivery apparatus comprises: a shaft having a proximal end portion, adistal end portion, a lumen extending from the proximal end portion tothe distal end portion, and a plurality of openings formed in the distalend portion, wherein the shaft is configured such that a fluid can flowthrough the lumen and the openings; an inner balloon having end portionsand a center portion disposed between the end portions, wherein theinner balloon is mounted on the distal end portion of the shaft and isin fluid communication with the openings of the shaft; and an outerballoon mounted to the shaft and disposed over the inner balloon,wherein the prosthetic heart valve is mounted over the outer balloon inthe compressed state and axially positioned relative to the innerballoon such that the inflow end portion and the outflow end portion ofthe prosthetic heart valve are aligned with the end portions of theinner balloon and the intermediate portion of the prosthetic heart valveis aligned with the center portion of the inner balloon, and whereinwhen the inner balloon is inflated, the end portions of the innerballoon at least partially inflate and the inflow and outflow endportions of the prosthetic heart valve at least partially radiallyexpand prior to the outer balloon fully expanding and the intermediateportion of the prosthetic heart valve fully radially expanding, andwherein the inner balloon includes pores that are configured to allow atleast some of the fluid to flow out of the inner balloon and into theouter balloon prior to the inner balloon reaching a predeterminedpressure, wherein the inner balloon is configured to burst at thepredetermined pressure, and wherein the outer balloon is configured tofully expand after the inner balloon bursts.
 10. The assembly of claim9, wherein when the inner balloon is inflated to a pressure less thanthe predetermined pressure, the end portions of the inner balloon arebulbous and taper radially inwardly to the center portion.
 11. Theassembly of claim 10, wherein when the inner balloon is inflated to apressure less than the predetermined pressure, the center portion iscylindrical.
 12. The assembly of claim 9, wherein when the outer balloonis fully inflated, the outer balloon and the prosthetic heart valve areradially spaced from inner balloon.
 13. The assembly of claim 9, whereinthe predetermined pressure is 1-5 bar.
 14. The assembly of claim 9,wherein the prosthetic heart valve and the delivery apparatus areconfigured for a transfemoral delivery procedure.